Information terminal device

ABSTRACT

Detection as to the reproduction expiration time of contents is executed, using the measured time of a system clock managed based on system time data from a base station BS. If the reproduction expiration time of the contents is not exceeded, the contents can be reproduced, whereas if it is exceeded, the contents are not reproduced, and a message “Expired” is generated and displayed on a display.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Applications No. 2001-367481, filed Nov. 30,2001; and No. 2001-367947, filed Nov. 30, 2001, the entire contents ofboth of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information terminal device such asa personal computer, mobile phone, etc., and more particularly to adevice equipped with a function for reproducing contents on or before anexpiration time.

2. Description of the Related Art

Many recent information terminal devices, such as notebook type personalcomputers, mobile phones, etc., are equipped with a function forreproducing contents received via a communication network or recorded ona recording medium. These devices are very convenient since they enableusers to enjoy contents, such as favorite music or images, anywhere.

In the meantime, contents, in which a reproduction valid term (forexample, the contents are reproducible only within three days of theirdownloaded date) or reproduction expiration time (for example, thecontents are reproducible on or before, for example, Nov. 30, 2001) isset for the protection of copyright, are now increasing. When suchcontents are reproduced, in conventional mobile communication terminals,the reproduction valid term or reproduction expiration time set for thecontents is compared with the present time of an internal clock. If thepresent time is within the reproduction valid term or on or before thereproduction expiration time, the contents are reproduced.

However, in general, internal clocks employed in information terminaldevices have errors caused by reference oscillators. Accordingly, whenthe errors are large, the reproduction term of contents cannot beaccurately managed. Further, the time of the internal clocks of suchdevices can be manually adjusted. Therefore, if a user intentionallychanges the time of the internal clock, contents remain reproducibleeven after their expiration time, which makes it impossible to preventunauthorized use of the contents.

Further, in general mobile communication systems, if an informationterminal device is positioned outside the service area of a basestation, or if it is within a building or under the ground even insidethe service area, it cannot receive system time data transmitted fromthe base station. Also, while the information terminal device is beingtransported at a high speed, it cannot sometimes receive the system timedata from the base station due to, for example, the fading phenomenon.

BRIEF SUMMARY OF THE INVENTION

The present invention has been developed in light of the abovecircumstances, and aims to provide an information communication terminalcapable of accurately managing the reproduction expiration time ofcontents.

According to a first aspect of the invention, there is provided aninformation terminal device having a function for reproducing contentsfor which a reproduction expiration time is preset, comprising: a firstclock whose measured time can be adjusted by a user; a receiverconfigured to receive standard time data transmitted from a transmitterstation; a time adjuster configured to adjust a value corresponding tothe measured time of the first clock based on the standard time datareceived by the receiver; a comparison unit configured to compare thereproduction expiration time of the contents with the value adjusted bythe time adjuster; a detection unit configured to detect whether or notthe value adjusted exceeds the reproduction expiration time of thecontents; and a reproduction controller configured to reproduce thecontents if the detection unit detects that the value adjusted does notexceed the reproduction expiration time of the contents.

According to a second aspect of the invention, there is provided aninformation terminal device having a function for reproducing contentsfor which a reproduction expiration time is preset, comprising: a firstclock whose measured time can be adjusted by a user; a second clock; areceiver configured to receive standard time data transmitted from atransmitter station; a time adjuster configured to adjust the measuredtime of the second clock based on the standard time data received by thereceiver; a comparison unit configured to compare the reproductionexpiration time of the contents with the time adjusted of the secondclock; a detection unit configured to detect whether or not the timeadjusted of the second clock exceeds the reproduction expiration time ofthe contents; and a reproduction controller configured to reproduce thecontents if the detection unit detects that the time adjusted of thesecond clock does not exceed the reproduction expiration time of thecontents.

According to a third aspect of the invention, there is provided aninformation terminal device having a function for reproducing contentsfor which a reproduction expiration time is preset, comprising: a timeacquisition unit configured to acquire a standard time from an externaldevice; an execution unit configured to execute time measurement basedon the standard time acquired; a first detection unit configured todetect whether a measured time of the execution unit is valid orinvalid; a second detection unit configured to detect whether or not themeasured time of the execution unit exceeds the reproduction expirationtime of the contents; and a reproduction controller configured toreproduce the contents if the first detection unit detects that themeasured time of the execution unit is valid and if the second detectionunit detects that the measured time of the execution unit does notexceed the reproduction expiration time of the contents.

According to a fourth aspect of the invention, there is provided aninformation terminal device having a function for reproducing contentsfor which a reproduction valid term is preset, comprising: a timeacquisition unit configured to acquire a standard time from an externaldevice; an execution unit configured to execute time measurement basedon the standard time acquired; a first detection unit configured todetect whether a measured time of the execution unit is valid orinvalid; and an expiration time setting unit configured to set areproduction expiration time for the contents based on the measured timeof the execution unit and the reproduction valid term of the contents,if the first detection unit detects that the measured time of theexecution unit is valid, the expiration time setting unit setting noreproduction expiration time if the first detection unit detects thatthe measured time of the execution unit is invalid.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention, and together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according to afirst embodiment of the invention;

FIG. 2 is a flowchart useful in explaining the details and procedure ofcontents reproduction control executed by the information terminaldevice of the first embodiment;

FIG. 3 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according to asecond embodiment of the invention;

FIG. 4 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according to athird embodiment of the invention;

FIG. 5 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according to afourth embodiment of the invention;

FIG. 6 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according to afifth embodiment of the invention;

FIG. 7 is a flowchart useful in explaining the details and procedure ofcontents reproduction control executed by the information terminaldevice shown in FIG. 6;

FIG. 8 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according to asixth embodiment of the invention;

FIG. 9 is the first half of a flowchart useful in explaining the detailsand procedure of contents reproduction control executed by theinformation terminal device shown in FIG. 8;

FIG. 10 is the last half of the flowchart useful in explaining thedetails and procedure of contents reproduction control executed by theinformation terminal device shown in FIG. 8; and

FIG. 11 is a block diagram illustrating an essential configuration of amobile communication terminal as an information terminal deviceaccording to a seventh embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(First Embodiment)

A CDMA mobile communication terminal according to a first embodiment ofthe invention employs a system clock for receiving system time data(usually including date information) transmitted from a base station,and executing time measurement based on the received data. When theterminal reproduces contents, it detects, if a reproduction expirationtime is set for the contents, whether or not the contents arereproducible, by comparing the reproduction expiration time with thepresent time of the system clock. If the contents are detectedreproducible, they are reproduced.

FIG. 1 is a block diagram illustrating the configuration of the mobilecommunication terminal as the information terminal device according tothe first embodiment of the invention. This mobile communicationterminal MS employs the CDMA (Code Division Multiple Access) system asthe radio communication method between the terminal and a base station.

A radio frequency signal transmitted from a base station BS is receivedby an antenna 1 and input to a receiving circuit (RX) 3 via an antennaduplexer (DUP) 2. The receiving circuit 3 mixes the radio frequencysignal with a receiving local oscillation signal output from a frequencysynthesizer (SYN) 4, with the result that the radio frequency signal isfrequency-converted into an intermediate frequency signal or basebandsignal. The frequency of the receiving local oscillation signalgenerated from the frequency synthesizer 4 is designated by a controlsignal SYC from a controller 12A.

The receiving intermediate frequency signal or receiving baseband signalis input to a CDMA signal processing unit 6. The CDMA signal processingunit 6 executes orthogonal demodulation processing, and despreadingprocessing using a spreading code assigned to the receiving channel, onthe receiving intermediate frequency signal or receiving basebandsignal. As a result, demodulated data of a predetected formatcorresponding to the data rate is obtained. The demodulated data isinput to a speech encoder 7. The control data contained in thedemodulated data, which indicates the data rate, is input, as receivingdata rate, to the controller 12A.

The speech encoder 7 executes decompression processing corresponding tothe receiving data rate reported from the controller 12A, on thedemodulated data output from the CDMA signal processing unit 6, and thenexecutes decoding processing using, for example, Viterbi decoding, anderror correction/decoding processing. As a result, a received digitaldata of a baseband is reproduced.

A PCM encoder 8 executes different signal processes between differenttypes of communication output from the controller 12A (speech or datacommunication). Specifically, when speech communication is executed, thePCM encoder 8 PCM-encodes the receiving digital data output from speechencoder 7 and outputs an analog receiving signal. This analog receivingsignal is amplified by a receiving signal amplifier 9 and output as aspeech from a loudspeaker 10. During image or data communication, thePCM encoder 8 sends the receiving digital data, output from the speechencoder 7, to the controller 12A. The controller 12A outputs thereceiving digital data in a memory 13 and displays it on a display 15.

When necessary, the receiving digital data can be transferred, via anexternal interface (not shown), to an external information terminal,such as a portable data terminal (PDA: Personal Digital Assistant), anotebook personal computer, etc., which are not shown.

On the other hand, the input voice of a loudspeaker during speechcommunication is input as an analog speech signal via a microphone 11,and is amplified to an appropriate level by a speech amplifier 18. Afterthat, the amplified signal is input to the PCM encoder 8. The PCMencoder 8 executes PCM encoding on the input analog speech signal. Theresultant transmission data is supplied to the speech encoder 7.Further, the data output from the external information terminal is inputto the controller 12A via an external interface (not shown), then inputto the speech encoder 7 via the PCM encoder 8 from the controller 12A.

During speech communication, the speech encoder 7 detects the energy ofinput voice based on the transmission audio data output from the PCMencoder 8, and detects the data rate from the detection result. Afterthat, the transmission data is compressed into a burst signal of aformat corresponding to the detected data rate, then subjected to errorcorrection coding, and output to the CDMA signal processing unit 6. Onthe other hand, during data communication, the transmission data outputfrom the PCM encoder 8 is compressed into a burst signal of a formatcorresponding to a preset data rate. After that, the compressedtransmission data is subjected to error correction coding and output tothe CDMA signal processing unit 6. The data rate during speech and datacommunication is reported, as a transmission data rate, to thecontroller 12A.

The CDMA signal processing unit 6 executes spread processing on theburst signal compressed by the speech encoder 7, using a spreading codeassigned to the transmission channel used. Thereafter, it executesorthogonal modulation on the transmission signal obtained by spreadcoding, and outputs the resultant orthogonal modulation signal to atransmission circuit (TX) 5.

The transmission circuit 5 synthesizes, into a radio frequency signal,the orthogonal modulation signal output from the CDMA signal processingunit 6, and a transmission local oscillation signal output from thefrequency synthesizer 4. Thereafter, the transmission circuit 5amplifies the higher frequency components of only the effective portionof the radio frequency signal based on the transmission data ratereported by the controller 12A, and outputs the resultant signal as atransmission radio frequency signal. The transmission radio frequencysignal output from the transmission circuit 5 is supplied to the antenna1 via the antenna duplexer 2, and burst-transmitted from the antenna 1to a base station (not shown).

An input unit 14 is provided with a key group that includes dial keys, acall origination key, power key, end key, volume key and modedesignation key, etc. The display 15 is provided with an LCD display andLED. The LCD display displays information memorized in a telephone book,the history of outgoing and/or incoming call, the phone number of acaller or person called, mail addresses, the operation state of theterminal, etc. Further, the LED is lightened or flickered to inform auser of a coming call, or to require the charge of a battery 16.

Reference numeral 17 denotes a power supply circuit, which generates apredetected operation power voltage Vcc based on the output of thebattery 16, and supplies it to each circuit unit. Further, the powersupply circuit 17 contains a charging circuit for charging the battery16.

The mobile communication terminal of this embodiment comprises theaforementioned memory 13 for memorizing, for example, contents, and auser clock 21 and system clock 22. Both the user clock 21 and systemclock 22 execute time measurement using an RTC (Real Time Clock).However, the user clock 21 can be manually operated by a user to executeoptional time setting, while the system clock 22 cannot be operated by auser. The system clock 22 executes time measurement in synchronism withsystem time data transmitted from a base station BS, in an idle state orduring communication.

The controller 12A is formed of, for example, a microcomputer as a maincontroller, and has standard control functions for mobile terminals,such as a communication control function for executing radio connectioncontrol in response to an outgoing or incoming call to enable speech ordata communication, a position registration control function, an idlehand-off control function, etc. The controller also has new controlfunctions according to the embodiment, such as a contents reproductioncontrol function 12 a and expiration time detecting function 12 b.

The expiration time detecting function 12 b detects, when contents arereproduced, whether or not a reproduction expiration time is set for thecontents. If the reproduction expiration time is set, the time measuredby the system clock 22 is compared with the reproduction expiration timeto detect whether the measured time is not after the reproductionexpiration time.

The contents reproduction control function 12 a reads the contents fromthe memory 13 and executes control for their reproduction, if theexpiration time detecting function 12 b detects that the time measuredby the system clock 22 is on or before the expiration time. On the otherhand, if it is detected that the measured time is after the expirationtime, reproduction of the contents is inhibited, and a message “Expired”is generated and displayed on the display 15.

The contents reproduction control function 12 a and expiration timedetecting function 12 b are each realized by making the microprocessorof the controller 12A execute a corresponding program. These programsare memorized in a program memory in the controller 12A or the programmemory area of the memory 13. The programs memorized in the programmemory or memory area may be prememorized therein by a program writerduring manufacture of the terminal, or may be read from an externalmemory such as a CD-ROM or memory card and written to the program memoryor program memory area when the use of the terminal is started, or maybe downloaded from a maker site via a communication network and writtento the program memory or program memory area.

A description will now be given of the contents reproduction operationof the mobile communication terminal constructed as above. FIG. 2 is aflowchart illustrating the procedure and details of contentsreproduction control executed by the controller 12A.

The memory 13 prememorizes contents. The contents are downloaded from,for example, a web site on the Internet, or transferred from an externalinformation device, such as a personal computer, via a cable or radiointerface such as Bluetooth, or read from a memory card. The contentsare thus fetched and memorized in the memory 13.

The time measured by the system clock 22 becomes unstable if the battery16 is removed. This unstable state is not eliminated simply by attachingthe battery 16 again, and continues until the controller 12A receivessystem time data from the base station BS and sets, as the present timeof the system clock 22, the time measured based on the received systemtime data. Upon the initial setting of the measured time, the systemclock 22 starts free-running time measurement based on RTC (Real TimeClock).

After the system clock 22 starts free-running time measurement, thecontroller 12A periodically receives the system time data, that istransmitted from the base station BS, during the idle state andcommunication state, and adjusts the time measured by the system clock22 based on the received system time data. Accordingly, the measuredtime of the system clock 22 is always synchronous with the system timeof the base station, and cannot be intentionally changed by a user.

The receiving of the system time data is executed by once switching thereceiving channel from the paging channel to the sync-channel, thenreceiving a sync-channel signal transmitted from the base station, andextracting system time data from the received synch-channel signal.

During the idle state, the controller 12A monitors, at a step S101, anoperation for reproducing contents executed by a user. In this state,assume that the user has designated the contents memorized in the memory13 and has executed the reproduction operation of the contents, usingthe input unit 14. At this time, firstly, the controller 12A activatesthe expiration time detecting function 12 b to read, from the memory 13at a step S102, time information corresponding to the designatedcontents, and to detect, at the next step S103, whether or notexpiration time data is set. If no expiration time data is set,reproduction of the contents is executed unconditionally at a step S107.

On the other hand, assume that expiration time data is set for thedesignated contents. In this case, the controller 12A proceeds to a stepS104, where it reads the time measured by the system clock 22. At thenext step S105, the controller 12A compares the measured time with theexpiration time data read from the memory 13, and detects at a step S106whether or not the reproduction expiration time of the designatedcontents is exceeded.

If the detection result indicates that the reproduction expiration timeof the designated contents is not exceeded, the controller 12A activatesthe contents reproduction control function 12 a to execute reproductionprocessing on the designated contents at a step S107. In thereproduction process, for example, the contents are read from the memory13, and it is detected whether they are audio contents such as music, orphoto contents such as a still image used as a wallpaper. If they areaudio contents, audio data is decoded and output from the loudspeaker 10via the PCM encoder 8 and receiving signal amplifier 9. On the otherhand, if they are photo contents, still image data is decoded anddisplayed on the display 15.

Further, if the contents are video contents formed of audio data andvideo data, audio data is decoded and output from the loudspeaker 10 viathe PCM encoder 8 and receiving signal amplifier 9, while video data isdecoded and displayed on the display 15. The audio data output operationis executed in synchronism with the video data display operation basedon a time stamp attached to the data.

If a loudspeaker dedicated to reproduction of audio contents is providedin addition to the receiving loudspeaker 10, audio data is controlled tobe output from the loudspeaker dedicated thereto. Further, if outputterminals for audio and video data are provided, audio and video dataare supplied to, for example, an external personal computer via theoutput terminals, where they are output and displayed.

When reproduction of contents has started, the controller 12A monitorsat a step S109 whether reproduction has finished, and returns to theidle state after reproduction finishes.

On the other hand, assume that it is detected at the step S106 that thereproduction expiration time of the designated contents is exceeded. Inthis case, the controller 12A does not execute a reproduction inhibitionprocess on the contents, and proceeds to a step S108, where a message“Expired” is generated and displayed on the display 15.

As described above, in the first embodiment, detection as to thereproduction expiration time of contents is performed, using themeasured time of the system clock 22 managed by the system time of thebase station BS, and the contents can be reproduced if theirreproduction expiration time is not exceeded. Thus, the detection as tothe reproduction expiration time of contents can be accurately executedwithout the influence of a clock error, compared to the conventionalcase where such detection is executed using the time measured by theuser clock 21. Moreover, regardless of a user's intentional change ofthe time of the user clock, unauthorized use of contents can be reliablyprevented.

If the reproduction expiration time of contents designated as ato-be-reproduced object is exceeded, reproduction of the contents is notexecuted, and a message “Expired” is generated and displayed on thedisplay 15. From this message, the user can recognize the expiration ofthe contents.

(Second Embodiment)

In a second embodiment, a GPS (Global Positioning System) receiver isused as means for externally acquiring a standard time, and system timedata is received from the GPS receiver when contents are reproduced. Bycomparing the received system time data with the reproduction expirationtime of the contents, it is detected whether or not the reproductionexpiration time of the contents is exceeded. If it is detected that thereproduction expiration time of the contents is not exceeded, thereproduction of the contents is permitted.

FIG. 3 shows the configuration of a mobile communication terminalaccording to the second embodiment. In FIG. 3, elements similar to thoseshown in FIG. 1 are denoted by corresponding reference numerals and arenot described in detail.

The mobile communication terminal of the second embodiment employs a GPSreceiver 30. The GPS receiver 30 receives GPS signals transmitted from aplurality of navigational satellites (not shown), extracts system timedata from the GPS signals, and supplies it to a controller 12B.

The controller 12B has a contents reproduction control function 12 a andexpiration time detecting function 12 c, as functions according to theembodiment.

The expiration time detecting function 12 c fetches system time datafrom the GPS receiver 30, if a request for reproduction of contents, forwhich a reproduction expiration time is set, is input. By comparing thefetched system time data with the reproduction expiration time of thecontents, the expiration time detecting function 12 c detects whether ornot the reproduction expiration time of the contents is exceeded.

The contents reproduction control function 12 a permits contents to bereproduced, if the expiration date detecting function 12 c detects thatthe reproduction expiration time of the contents is not exceeded. On theother hand, if the function 12 c detects that the reproductionexpiration time of the contents is exceeded, the function 12 a inhibitsreproduction of the contents, and displays a message “Expired” on thedisplay 15.

In the above-described structure, detection as to the reproductionexpiration time of contents is executed based on system time data eachtime the GPS receiver 30 receives the system time data. Accordingly,compared to the conventional case where detection is executed using thetime measured by the user clock 21, accurate detection as to thereproduction expiration time of contents can be performed without beinginfluenced by a clock error. Moreover, regardless of a user'sintentional change of the time of the user clock, unauthorized use ofcontents can be reliably prevented.

Further, if the reproduction expiration time of contents designated as ato-be-reproduced object is exceeded, reproduction of the contents is notexecuted, and a message “Expired” is generated and displayed on thedisplay 15. From this message, the user can recognize the expiration ofthe contents.

The use of the GPS receiver 30 as standard time acquisition meansenables the embodiment to be applied in a system, other than the CDMAmobile communication system, such as the TDMA (Time Division MultipleAccess) mobile communication system or an analog mobile communicationsystem, in which a base station does not transmit system time data.

(Third Embodiment)

In the first embodiment, the system clock 22 having its measured timeadjusted by received system time data is provided as well as the userclock 21, and detection as to the reproduction expiration of contents isperformed based on the time measured by the system clock 22.

However, the invention is not limited to this. It may be modified suchthat when a request for reproduction of contents has been input, thetime measured by the user clock is adjusted based on the received systemtime data, and detection as to the reproduction expiration time of thecontents is performed based on the adjusted time.

FIG. 4 is a block diagram illustrating the configuration of a mobilecommunication terminal as an information terminal device according tothe third embodiment of the invention. In FIG. 4, elements similar tothose shown in FIG. 1 are denoted by corresponding reference numerals. Acontroller 12C also has an expiration time detecting function 12 d andtime adjustment function 12 e.

The time adjustment function 12 e is used to receive updated system timedata from a base station BS and properly adjust the time measured by theuser clock 21 based on the received system time data, when a request forreproduction of contents, for which a reproduction expiration time isset, has been input from the input unit 14.

The expiration time detecting function 12 d fetches the properlyadjusted time from the time adjustment function 12 e, and compares thefetched time with the reproduction expiration time of the contents todetect whether or not the reproduction expiration time is exceeded.

The contents reproduction control function 12 a enables reproduction ofcontents if the expiration time detecting function 12 d detects that thereproduction expiration time of the contents is not exceeded. On theother hand, if the expiration time detecting function 12 d detects thatthe reproduction expiration time of the contents is exceeded, thecontents is not reproduced, and a message “Expired” is generated anddisplayed on the display 15.

In the above-described configuration, since detection as to thereproduction expiration time is performed based on the measured time ofthe user clock 21 adjusted based on the system time data, accuratedetection can be always executed. Furthermore, since the time measuredby the user clock 21 is utilized, the system clock 22 is not necessary,and accordingly the configuration can be simplified. This embodiment issuitable for terminals, other than the CDMA mobile communicationterminal, in which the system clock is not standard equipment.

(Fourth Embodiment)

In the configuration of FIG. 4, the measured time of the user clock 21is automatically adjusted to the system time whenever contents arereproduced. Therefore, if a user changes the time of the user clock 21to any optionally selected time, for example, if the user advance thetime of the user clock by a predetected time, the user must reset thetime of the user clock 21 each time the time of the user clock isautomatically adjusted to the system time.

To avoid this inconvenience, a time correction function is employed. Ifa request for reproduction of contents is input, the time output fromthe user clock 21 is corrected based on received system time data, anddetection as to the reproduction expiration time of contents isperformed based on the corrected time.

FIG. 5 is a block diagram illustrating the configuration of an essentialpart of a mobile communication terminal according to the fourthembodiment of the invention. In FIG. 5, elements similar to those shownin FIG. 1 are denoted by corresponding reference numerals. The mobilecommunication terminal of this embodiment incorporates a controller 12Dthat has a contents reproduction control function 12 a, expiration timedetecting function 12 f and time correction function 12 g.

The time correction function 12 g corrects the time output from the userclock 21, based on received system time data.

The expiration time detecting function 12 f fetches the time correctedby the time correction function 12 g, when a request for reproduction ofcontents has been input. By comparing the fetched time with thereproduction expiration time of the contents, the function 12 f detectswhether or not the reproduction expiration time is exceeded.

The contents reproduction control function 12 a permits contents to bereproduced, if the expiration date detecting function 12 f detects thatthe reproduction expiration time of the contents is not exceeded. On theother hand, if the function 12 f detects that the reproductionexpiration time of the contents is exceeded, the function 12 a inhibitsreproduction of the contents, and displays a message “Expired” on thedisplay 15.

In the above-described configuration, for detection as to the expirationtime of contents, the time obtained by correcting the time output fromthe user clock 21 based on system time data is used. Thus, the detectionas to the reproduction expiration time can be always executed using theaccurate time corrected based on the system time data, with the resultthat accurate detection is realized and the system clock 22 can beomitted.

Moreover, since the measured time of the user clock 21 itself is notadjusted, even if a user changes the time of the user clock 21 to anyoptionally selected time, for example, if the user advance the time ofthe user clock by a predetected time, the user do not have to reset thetime of the user clock 21. Thus, the operability is enhanced.

Further, the invention can he modified in various ways.

For example, although the second embodiment employs the GPS receiver 30as means for acquiring a standard time, a standard time receiver may beemployed instead of the GPS receiver so that a standard time transmittedfrom a standard time broadcast station will be received and used.

In each of the above-described embodiments, if the reproductionexpiration time is exceeded, a message “Expired” is generated anddisplayed. However, a message “Not Expired” may be generated anddisplayed as well as “Expired”. In this case, it is advisable to displaythe remaining date and/or time as well as the message “Not Expired”.

As means for reporting that contents cannot be reproduced, a voicemessage may be output from the loudspeaker 10, as well as a lettermessage displayed on the display 15.

Furthermore, in each embodiment, the contents, for which a reproductionexpiration time is set, are described. However, the invention is alsoapplicable to the contents for which a reproduction valid term is set.In this case, a reproduction expiration time is set from thereproduction valid term and a start time of use, the time of the userclock adjusted based on system time data, or the measured time of thesystem clock being used as the start time of use. In other words, areproduction valid term is converted into a reproduction expirationtime, and it is detected whether contents are reproducible, using theresultant reproduction expiration time.

In addition, in each embodiment, a CDMA mobile communication terminal isused as an information terminal device. However, a mobile communicationterminal that employs another radio communication method, such as a TDMAmobile communication terminal, analog mobile communication terminal,etc., may be used instead. Further, the invention is not limited tomobile communication terminals, but is also applicable to portableelectronic devices such as notebook type personal computers, audioplayers, video reproduction apparatuses, game machines, clocks, etc., orto stationary personal computers, audio players, etc.

As described above, detection as to the reproduction expiration time ofcontents can be always executed based on a standard time, using nointernal clock. Thus, the invention can provide an information terminaldevice capable of accurate detection as to a reproduction expirationtime irrespective of an error in the time measured by the internalclock, and hence capable of preventing unauthorized use of contentsregardless of a user's intentional change of the time of the internalclock.

Even if there is an error in the time measured by a first clock that canbe adjusted by a user, or even if a user intentionally changes the timeof the first clock, the time of the first clock is used for detection asto a reproduction expiration time after it is adjusted based on astandard time received. Accordingly, accurate reproduction expirationtime detection can be always performed by adding a simple device to theexisting first clock.

Furthermore, if a user changes the time of the first clock to anarbitrary time, the time output from the first clock is used fordetection as to the reproduction expiration time of contents after it iscorrected based on standard time data. Accordingly, accuratereproduction expiration time detection can be always performed using theexisting first clock. Also, since the first clock itself is notadjusted, and the time output therefrom is corrected based on standardtime data, it is not necessary for the user to reset the first clock totheir desired time.

Further, detection as to the reproduction expiration time of contentscan be performed using the time measured by a second clock operableindependent of the first clock. Accordingly, the reproduction expirationtime detection can be always accurately performed without depending uponthe first clock.

A system time corresponding to a standard time can be acquired using theexisting mobile communication function. In other words, it is notnecessary to employ any new receiving means for acquiring standard timedata. Thus, accurate reproduction expiration time detection can berealized by a simple structure.

System time data can be acquired anywhere if a signal from anavigational satellite can be received. Therefore, an informationterminal device having an expiration time detecting function can be usedin an extremely wide area, compared to the case of acquiring system timedata from a mobile communication base station.

The mobile communication terminal of the invention further comprisesmessage reporting means for generating a message “Expired” and reportingthe fact to a user, if it is detected that the measured time is afterthe reproduction expiration time of contents. This enables the user toknow the reason why the contents are not reproduced.

(Fifth Embodiment)

In a fifth embodiment, when the contents, for which a reproductionexpiration time is set, are reproduced, it is detected whether or notthe time measured by the system clock is valid. If the time measured bythe system clock is valid, detection as to the reproduction expirationtime is executed based on the measured time, and the reproduction of thecontents is allowed if the reproduction expiration time is not exceeded.On the other hand, if the time measured by the system clock is invalid,neither detection as to the reproduction expiration time norreproduction of the contents is executed.

FIG. 6 is a block diagram illustrating a mobile communication terminalMS as an information terminal device according to the fifth embodiment.This mobile communication terminal MS employs the CDMA (Code DivisionMultiple Access) system as the radio communication method between theterminal and a base station BS. In FIG. 6, elements similar to thoseshown in FIG. 1 are denoted by corresponding reference numerals and arenot described in detail.

The mobile communication terminal has new control functions according tothe embodiment, such as an expiration time detecting function 12 h,system time valid/invalid detecting function 12 i and system timeacquisition adjusting function 12 j.

The system time acquisition adjusting function 12 j periodicallyreceives system time data transmitted from a base station upon turn-on,and during an idle state and communication state. Based on the receivedsystem time data, setting and adjustment of the system clock 22 isexecuted.

The system time valid/invalid detecting function 12 i detects whether ornot the time measured by the system clock 22 is valid, when a requestfor reproduction of contents has been input. If the measured time isdetected invalid, a message indicative of it is displayed on the display15. Detection as to the validity/invalidity of the measured time isperformed in the following manner.

The time measured by the system clock 22 becomes unstable if the battery16 is removed. This unstable state is not eliminated simply by attachingthe battery 16 again, and continues until the system time acquisitionadjusting function 12 j receives system time data transmitted from abase station BS, and executes initial setting of the system clock 22based on the received system time data. This unstable state is definedas an “invalid” state. Upon initial setting of the time, the systemclock 22 starts free-running time measurement based on RTC (Real TimeClock), and the measured time of the system clock 22 is automaticallyadjusted based on the system time data received periodically. This timemeasurement state is defined as a “valid” state. Whether the state ofthe system clock 22 is “valid” or “invalid” is detected by referring to,for example, a flag that indicates the state of the system clock 22 andis memorized in a memory in a controller 12E.

The expiration time detecting function 12 h is activated if the systemtime valid/invalid detecting function 12 i detects that the measuredtime of the system clock 22 is valid. Firstly, the function 12 h detectswhether or not a reproduction expiration time is set for the contents.If the reproduction expiration time is set, the function 12 h comparesthe time measured by the system clock 22 with the reproductionexpiration time, thus detects whether the measured time is not after thereproduction expiration time.

The contents reproduction control function 12 a reads the contents fromthe memory 13 and executes reproduction control for them, if theexpiration time detecting function 12 h detects that the measured timeis not after the reproduction expiration time. On the other hand, if theexpiration time detecting function 12 h detects that the measured timeis after the reproduction expiration time, the contents reproductioncontrol function 12 a does not execute reproduction control for thecontents, and generates a message “Expired” and displays it on thedisplay 15.

The contents reproduction control function 12 a, expiration timedetecting function 12 h, system time valid/invalid detecting function 12i and system time acquisition adjusting function 12 j are all realizedby making the microprocessor of the controller 12E execute respectiveprograms. These programs are memorized in the program memory of thecontroller 12E or the program memory area of the memory 13. The programsmemorized in the program memory or memory area may be prememorizedtherein by a program writer during manufacture of the terminal, or maybe read from an external memory such as a CD-ROM or memory card andwritten to the program memory or program memory area when the use of theterminal is started, or may be downloaded from a maker site via acommunication network and written to the program memory or programmemory area.

A description will now be given of the contents reproduction operationof the mobile communication terminal constructed as above. FIG. 7 is aflowchart illustrating the procedure and details of contentsreproduction control executed by the controller 12E. In FIG. 7, elementssimilar to those shown in FIG. 2 are denoted by corresponding referencenumerals and are not described in detail.

Assume that expiration time information is set for the designatedcontents. In this case, the controller 12E proceeds to a step S2041where it receives system time data from the base station BS, using thesystem time acquisition adjusting function 12 j. Specifically, thesystem time data is received by once switching the receiving channelfrom the paging channel to the sync-channel, receiving a sync-channelsignal transmitted from the base station, and extracting system timedata from the received sync-channel signal. Subsequently, the controller12E adjusts the time measured by the system clock 22 based on thereceived system time data. After that, the controller 12E proceeds astep S2042, where it detects, using the system time valid/invaliddetecting function 12 i, whether the measured time of the system clock22 is valid or invalid.

Assume, for example, that no initial value is set in the system clock22, and no system time data is received from the base station via thesystem time acquisition adjusting function 12 j. In this case, thecontroller 12E detects that the time measured by the system clock 22 is“invalid”, and proceeds to a step S208 where a reproduction disapprovalmessage, which indicates that the contents cannot be reproduced, isgenerated and displayed on the display 15. This message includes thereason for the non-reproducible state and a message that recommendsmovement to a radio wave receivable place. From the displayed message,the user can recognize that detection as to the reproduction expirationtime cannot be performed because no radio wave can be received.

On the other hand, assume that the system clock 22 is normally executingtime measurement, and the system time valid/invalid detecting function12 i has detected “valid”. In this case, the controller 12E proceeds toa step S205 where the expiration time detecting function 12 h isactivated to fetch the time, measured by the system clock 22, via thesystem time valid/invalid detecting function 12 i. The expiration timedetecting function 12 h then compares the time measured by the systemclock 22, with the reproduction expiration time previously read from thememory 13, thereby detecting at a step S106 whether or not thereproduction expiration time of the designated contents is exceeded.

Assume that the reproduction expiration time of the designated contentsis exceeded as a result of the detection at the step S106. In this case,the controller 12E does not execute the reproduction of the contents,and proceeds to a step S208 where it generates a message “Expired” anddisplays it on the display 15. Thus, the user can recognize, from thedisplay message, that the expiration time of the designated contents isexceeded.

As described above, in the fifth embodiment, before detection as to thereproduction expiration time of contents, it is detected whether or notthe time measured by the system clock 22 is valid. If it is detectedvalid, detection as to the reproduction expiration time is executedbased on the measured time of the system clock 22. If it is confirmedfrom the detection that the reproduction expiration time is notexceeded, the contents are read from the memory 13 and reproduced. Onthe other hand, if the measured time of the system clock 22 is invalid,or if the reproduction expiration time of the contents is exceeded, thecontents are not reproduced, and a message indicative of the reason isgenerated and displayed on the display 15.

Thus, in this embodiment, the use of the measured time of the systemclock 22 that is adjusted to the system time transmitted from the basestation BS and cannot be adjusted by users enables detection as to thereproduction expiration time of contents to be executed accuratelyregardless of an error in measured time, and also enables unauthorizeduse of contents to be reliably prevented.

Further, if the measured time of the system clock 22 is invalid,detection as to the reproduction expiration time is not executed. Thus,reproduction expiration time detection is not executed if system timedata cannot be received from the base station BS. This means thatreproduction expiration time detection can be executed always based onaccurate time, and hence highly reliable expiration time management canbe realized.

Furthermore, if the measured time of the system clock 22 is invalid, orif the reproduction expiration time of contents designated as ato-be-reproduced object is exceeded, a message indicative of this isgenerated and displayed on the display 15. From the display message,users can clearly recognize the reason why the designated contents arenot reproduced.

(Sixth Embodiment)

In a sixth embodiment of the invention, when a reproduction expirationtime is set for the contents, for which a reproduction valid term, suchas one month from the start of use, is set, it is detected whether ornot the measured time of the system clock 22 is valid, and if it isdetected valid, the reproduction expiration time is set for the contentsbased on the measured time of the system clock 22 and reproduction validterm. Further, also when the contents, for which the reproductionexpiration time is set, are reproduced, it is detected whether or notthe measured time of the system clock 22 is valid, and if it is detectedvalid, detection as to the reproduction expiration time is executedbased on the measured time of the system clock 22. Only if it isconfirmed, as a result of the detection, that the measured time is on orbefore the reproduction expiration time, the contents can be reproduced.

FIG. 8 is a block diagram illustrating a mobile communication terminalaccording to the sixth embodiment. In FIG. 8, elements similar to thoseshown in FIG. 6 are denoted by corresponding reference numerals and arenot described in detail.

A controller 12F has, as control functions according to the sixthembodiment, a contents reproduction control function 12 a, expirationtime determining function 12 h, system time valid/invalid determiningfunction 12 i, system time acquisition adjusting function 12 j, andexpiration time setting function 12 k.

The expiration time setting function 12 k sets a reproduction expirationtime based on the measured time of the system clock 22 and areproduction valid term, if the reproduction valid term is set asexpiration time information for to-be-reproduced contents. Before thesetting, the system time valid/invalid determining function 12 i detectswhether or not the measured time of the system clock 22 is valid. If itis detected valid, the expiration time setting function 12 k executes aprocess for setting the reproduction expiration time. Further, if themeasured time of the system clock 22 is invalid, the setting of thereproduction expiration time is not executed, and a message indicativeof it is generated and displayed on the display 15.

The operation of reproducing contents by the mobile communicationterminal constructed as above will be described. FIGS. 9 and 10 are thefirst and latter halves of a flowchart useful in explaining the detailsand procedure of contents reproduction control executed by thecontroller 12F, respectively. In FIGS. 9 and 10, steps similar to thoseshown in FIG. 2 or 7 are denoted by corresponding reference numerals andare not described in detail.

Assume that expiration time information is set for designated contents.In this case, the controller 12F proceeds to a step S303 where itdetects whether the type of expiration time information is “expirationtime” or “valid term”.

If, for example, the type of expiration time information is “validterm”, the controller 12F receives, at a step S3041, system time datafrom a base station BS, using the system time acquisition adjustingfunction 12 j. Specifically, the system time data is received by onceswitching the receiving channel from the paging channel to thesync-channel, receiving a sync-channel signal transmitted from the basestation, and extracting system time data from the received sync-channelsignal. Subsequently, the controller 12F adjusts the measured time ofthe system clock 22 based on the received system time data. After that,the controller 12F proceeds a step S3042, where it detects, using thesystem time valid/invalid determining function 12 i, whether themeasured time of the system clock 22 is valid or invalid.

Assume, for example, that no initial value is set in the system clock22, and no system time data is received from the base station via thesystem time acquisition adjusting function 12 j. In this case, thecontroller 12F detects that the time measured by the system clock 22 is“invalid”, and proceeds to a step S308 where a message, which indicatesthat a reproduction expiration time cannot be set for the contents, isgenerated and displayed on the display 15. This message includes thereason for the non-reproducible state and a message that recommendsmovement to a radio wave receivable place. From the display message, theuser can recognize that the reproduction expiration time cannot be setbecause no radio wave can be received.

On the other hand, assume that the system clock 22 is normally executingtime measurement, and the system time valid/invalid determining function12 i has detected “valid”. In this case, the controller 12F proceeds toa step S3043 where a reproduction expiration time is set for thedesignated contents. If it is not set, a process for setting thereproduction expiration time is executed at a step S3044. Thereproduction expiration time is set to a time obtained by adding thereproduction valid term to the measured time of the system clock 22.

After the expiration time is set, the controller 12F proceeds to thestep S205 where the expiration time determining function 12 h isactivated to fetch the time measured by the system clock 22, using thesystem time valid/invalid determining function 12 i. The expiration timedetermining function 12 h then compares the measured time of the systemclock 22 with the reproduction expiration time set at the step S3044,thereby determining at the step S106 whether or not the reproductionexpiration time of the designated contents is exceeded.

On the other hand, assume that the detection result at the step S106indicates that the reproduction expiration time of the designatedcontents is exceeded. In this case, the controller 12F does not executethe reproduction of the contents, and proceeds to a step S308 where itgenerates a message “Expired” and displays it on the display 15. Thus,the user can recognize, from the display message, that the expirationtime of the designated contents is exceeded.

If the detection result at the step S303 indicates that the type ofexpiration time information is “expiration time”, the controller 12Fproceeds to the step S2042 shown in FIG. 7. Through the stepsS2042–S109, it is detected whether or not the measured time of thesystem clock 22 is valid, and whether or not the reproduction expirationtime of the contents is exceeded. If both the conditions are satisfied,the contents are reproduced.

As described above, in the sixth embodiment, before a reproductionexpiration time is set for contents, it is detected whether or not thetime measured by the system clock 22 is valid. If it is detected valid,the reproduction expiration time is set based on the measured time ofthe system clock 22 and reproduction valid term. Accordingly, theinconvenience can be avoided, in which a reproduction expiration time isset even if no system time data from the base station BS can be receivedand hence the measured time of the system clock 22 is unstable. As aresult, an accurate reproduction expiration time can be set all thetime.

Further, if the measured time of the system clock 22 is invalid, amessage indicative of the reason is generated and displayed on thedisplay 15. From the display message, users can clearly recognize thereason why a reproduction expiration time is not set for the designatedcontents.

(Seventh Embodiment)

In a seventh embodiment of the invention, if contents cannot bereproduced after their reproduction expiration time is set, because themeasured time of the system clock is invalid, then the number of daysthe invalid state is continued is counted. The reproduction expirationtime is automatically elongated by the number of days the contents couldnot be reproduced.

FIG. 11 is a block diagram illustrating a mobile communication terminalaccording to the seventh embodiment. In FIG. 11, elements similar tothose shown in FIG. 8 are denoted by corresponding reference numeralsand are not described in detail.

A controller 12G has, as control functions according to the seventhembodiment, a contents reproduction control function 12 a, expirationtime determining function 12 h, system time valid/invalid determiningfunction 12 i, system time acquisition adjusting function 12 j, andexpiration time setting function 12 l.

The expiration time setting function 12 l includes an expiration timeinitial value setting function 12 m and expiration time extendingfunction 12 n.

The expiration time initial value setting function 12 m sets an initialreproduction expiration time based on the measured time of the systemclock 22 and a valid term, if the valid term is set as expiration timeinformation for to-be-reproduced contents. Before the setting of theinitial expiration time, the system time valid/invalid determiningfunction 12 i detects whether or not the measured time of the systemclock 22 is valid. If the measured time is detected valid, the initialreproduction expiration time is set. On the other hand, if the measuredtime of the system clock 22 is invalid, the initial value of thereproduction expiration time is not set, and a message indicating thatno initial value is set is generated and displayed on the display 15.

After the expiration time initial value setting function 12 m sets theinitial value of the reproduction expiration time, if detection as tothe reproduction expiration time is not executed and the systeminformation cannot be reproduced, because the measured time of thesystem clock 22 is invalid, the expiration time extending function 12 nmeasures, in units of, for example, days, the time period in which noreproduction could be executed. After that, the function 12 n extendsthe initial reproduction expiration time by the counted days, and resetsthe expiration time to the extended value.

In the above-described structure, assume that a user has exchanged thebattery 16 for another after setting the initial value of thereproduction expiration time. At this time, the measured time of thesystem clock 22 becomes unstable. This unstable state is eliminated, ifthe mobile communication terminal MS receives system time datatransmitted from a base station BS after the power supply is turned onagain, and if the present time of the system clock 22 is reset based onthe received time data. However, if the mobile communication terminal MSis placed outside the service area of the base station BS, no systemtime data can be received from the base station BS, therefore thepresent time of the system clock 22 is not reset and is maintainedunstable. In other words, in this state, the user cannot reproducecontents, and nevertheless, their reproduction valid term is reduced.

In the seventh embodiment, however, if the measured time of the systemclock 22 is detected invalid after it is reset, the controller 12Gcounts the days invalidation detection occurred, extends thereproduction expiration time by the counted days, and resets thereproduction expiration time to the extended value. Thus, if theterminal cannot receive a radio wave from the base station BS, itautomatically extends the reproduction expiration time of contents.

Therefore, the user can make full use of the reproduction valid terminitially set for contents to reproduce the contents.

If the reproduction expiration time is automatically extended, it isadvisable to display a message indicative of the fact. It is alsoadvisable to display the extended expiration date or remaining days ortime, as well as the message.

In each embodiment, system time data broadcasted from a CDMA basestation is received as an external standard time. However, the inventionis not limited to this, but may be modified such that the system timedata may be received, using a GPS (Global Positioning System) receiver,when contents are reproduced. Further, a standard time receiver may beused instead of the GPS receiver, thereby receiving standard timeinformation broadcasted from a standard time broadcasting station.

Further, the reproduction disapproval message may be a voice messagecreated by a voice synthesizing function and output from the loudspeaker10, as well as a message displayed on the display 15.

Furthermore, although in each embodiment, a CDMA mobile communicationterminal is employed as an example of the information terminal device, amobile communication terminal, such as a TDMA mobile communicationterminal or analog mobile communication terminal, which uses anotherradio communication method, may be employed. Also, the invention is notlimited to mobile communication terminals, but may be directed toportable electronic apparatuses, such as notebook type personalcomputers, audio players, video reproduction apparatuses, game machines,clocks, etc., or to stationary personal computers, audio players, etc.

In the information terminal devices of the above-described fifth toseventh embodiments, if the information terminal device is located at,for example, a place where it cannot receive a radio wave transmittedfrom a station for broadcasting a standard time, and hence if it cannotacquire the standard time, the time measured by the time measurementmeans is detected invalid, thereby preventing detection as to thereproduction expiration time of contents. As a result, accuratedetection as to the reproduction expiration time of contents can bealways executed.

Further, in the information terminal devices, when they set areproduction expiration time for the contents for which a reproductionvalid term is set, the reproduction expiration time is prevented frombeing set based on an erroneously measured time, and therefore can beaccurately managed.

Also in the information terminal devices, unnecessary detection is notexecuted. Accordingly, the load on the controller and hence the powerconsumption of the devices can be reduced.

If the time measured by the time measurement means is detected invalid,it is advisable to generate and display a message indicative of it. Inthis case, users can clearly know the reason when the expiration time isnot set.

When, for example, contents cannot be reproduced even if theirreproduction expiration time is not exceeded, as in the case where aradio wave transmitted from a station for broadcasting a standard timecannot be received, the number of days reproduction was impossible iscounted, and the expiration time is automatically extended by thecounted days. Thus, users can use all the designated reproductionexpiration time for reproduction of contents.

In addition, modification can also be made, without departing from thescope of the invention, to the procedures and details of controlexecuted by the system time expiration valid/invalid determiningfunction, expiration time setting function, expiration time determiningfunction and contents reproduction control function, and to the type,form, structure, etc. of contents.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. An information terminal having a function for reproducing contentsfor which a reproduction expiration time is preset, said informationterminal having a first clock being capable of adjusting by a user andconfigured to generate a time output; a receiver configured to receivestandard time data transmitted from a base station; a comparison unit; adetection unit; and a reproduction controller, wherein the improvementcomprises; a time adjuster configured to adjust the time output based onthe standard time data received by the receiver; said comparison unitconfigured to compare the reproduction expiration time of the contentswith the adjusted time output; said detection unit configured to detectwhether or not the adjusted time output exceeds the reproductionexpiration time of the contents; and said reproduction controllerconfigured to reproduce the contents if the detection unit detects thatthe adjusted time output does not exceed the reproduction expirationtime of the contents.
 2. The information terminal according to claim 1,wherein the base station belongs to a CDMA (Code Division MultipleAccess) system, and the receiver receives system time data from the basestation.
 3. The information terminal according to claim 1, wherein whenthe information terminal is provided with a global navigation satellitesystem receiving function, the receiver receives system time datatransmitted from a navigation satellite, using the global navigationsatellite system receiving function.
 4. The information terminalaccording to claim 3, wherein when the global navigation satellitesystem is a GPS (Global Positioning System).
 5. The information terminalaccording to claim 1, further comprising a generating unit whichgenerates a message indicating that the time output exceeds thereproduction expiration time of the contents, if the detection unitdetects that the time output exceeds the reproduction expiration time ofthe contents.
 6. An information terminal having a function forreproducing contents for which a reproduction expiration is preset, saidinformation terminal having a first clock being capable of adjusting bya user and configured to generate first time information; a comparisonunit; a detection unit; a reproduction controller, wherein theimprovement comprises: a second clock being incapable of adjusting by auser and configured to generate second time information; a receiverconfigured to receive standard time data transmitted from a basestation; a clock adjuster configured to adjust the second timeinformation based on the standard time data received by the receiver;said comparison unit configured to compare the reproduction expirationtime of the contents with the adjusted second time information; saiddetection unit configured to detect whether or not the adjusted secondtime information exceeds the reproduction expiration time of thecontents; and said reproduction controller configured to reproduce thecontents if the detection unit detects that the adjusted second timeinformation does not exceed the reproduction expiration time of thecontents.
 7. The information terminal device according to claim 6,wherein the base station belongs to a CDMA (Code Division MultipleAccess) system, and the receiver receives system time data from the basestation.
 8. The information terminal according to claim 6, furthercomprising a generating unit which generates a message indicating thatthe adjusted second time information exceeds the reproduction expirationtime of the contents, if the detection unit detects that the adjustedsecond time information exceeds the reproduction expiration time of thecontents.
 9. An information terminal device having a function forreproducing contents for which a reproduction expiration time is preset,said information terminal having a first clock being capable ofadjusting by a user and configured to generate first time information; afirst detection unit; a reproduction controller, wherein the improvementcomprises: a second clock being incapable of adjusting by a user andconfigured to generate second time information; a receiver configured toreceive standard time data transmitted from a base station; a clockadjuster configured to adjust the second clock based on the standardtime data received by the receiver; said first detection unit configuredto detect whether the second time information is a valid state or aninvalid state, wherein the valid state indicates that a battery isattached to the information terminal, and the invalid state indicatesthat the battery is removed from the information terminal; a seconddetection unit configured to detect whether or not the second timeinformation exceeds the reproduction expiration time of the contents;and said reproduction controller configured to reproduce the contents ifthe first detection unit detects that the second time information is thevalid state and if the second detection unit detects that the secondtime information does not exceed the reproduction expiration time of thecontents.
 10. The information terminal device according to claim 9,wherein the reproduction controller includes a generating function whichgenerates a message indicating that the second time information is theinvalid state, if the first detection unit detects that the second timeinformation is the invalid state.
 11. The information terminal accordingto claim 9, wherein the second detection unit does not execute detectionas to whether or not the second time information exceeds thereproduction expiration time of the contents, if the first detectionunit detects that the second time information is the invalid state. 12.The information terminal according to claim 9, wherein the valid stateindicates that the battery is attached to the information terminal, thereceiver receives the standard time data, and the clock adjuster adjustthe second clock based on the standard time data.
 13. An informationterminal having a function for reproducing contents for which areproduction valid term is preset, said information terminal having afirst clock being capable of adjusting by a user and configured togenerate first time information; a first detection unit; wherein theimprovement comprises: a second clock being incapable of adjusting by auser and configured to generate second time information; a receiverconfigured to receive standard time data transmitted from a basestation; a clock adjuster configured to adjust the second timeinformation based on the standard time data received by the receiver;said first detection unit configured to detect whether the second timeinformation is a valid state or an invalid state, wherein the validstate indicates that a battery is attached to the information terminal,and the invalid state indicates that the battery is removed from theinformation terminal; and an expiration time setting unit configured toset a reproduction expiration time for the contents based on the secondtime information and the reproduction valid term of the contents, if thefirst detection unit detects that the second time information is thevalid state, and not to set the reproduction expiration time if thefirst detection unit detects that the second time information is theinvalid state.
 14. The information terminal according to claim 13,wherein the expiration time setting unit includes a generating functionwhich generates a message indicating that the second time information isthe invalid state, if the first detection unit detects that the secondtime information is the invalid state.
 15. The information terminalaccording to claim 13, further comprising: a second detection unitconfigured to detect whether or not the second time information exceedsthe reproduction expiration time set by the expiration time settingunit; and a reproduction controller configured to reproduce the contentsif the second detection unit detects that the second time informationdoes not exceed the reproduction expiration time set by the expirationtime setting unit.
 16. The information terminal according to claim 15,wherein the reproduction controller does not reproduce the contents ifthe first detection unit detects that the second time information is theinvalid state.
 17. The information terminal device according to claim16, further comprising: an expiration time detection unit configured todetect, after the expiration time setting unit sets the reproductionexpiration time, a time period, in which the contents could not bereproduced, based on the detection result of the first detection unit;and an expiration time extending unit configured to extend thereproduction expiration time based on the detected time period.
 18. Theinformation terminal according to claim 15, wherein the reproductioncontroller includes a generating function which generates a messageindicating that the second time information is the invalid state, if thefirst detection unit detects that the second time information is theinvalid state.
 19. The information terminal according to claim 13,wherein the valid state indicates that the battery is attached to theinformation terminal, the receiver receives the standard time data, andthe clock adjuster adjust the second clock based on the standard timedata.
 20. An information terminal for reproducing contents for which areproduction expiration is preset, said information terminal having afirst clock being capable of adjusting by a user and configured togenerate first time information; a comparison unit; a detection unit;and a reproduction unit, wherein the improvement comprises: a secondclock being incapable of adjusting by a user and configured to generatesecond time information; a receiver configured to receive standard timedata transmitted from a base station; a clock adjuster configured toadjust the second time information based on the standard time datareceived by the receiver; said comparison unit configured to compare thereproduction expiration time of the contents with the adjusted secondtime information; said detection unit configured to detect whether ornot the adjusted second time information exceeds the reproductionexpiration time of the contents; and said reproduction controllerconfigured to reproduce the contents if the detection unit detects thatthe adjusted second time information does not exceed the reproductionexpiration time of the contents, thereby preventing reproduction of saidcontents after said expiration time.
 21. An information terminal havinga function for reproducing contents for which a reproduction expirationtime is preset, said information terminal having a first clock beingcapable of adjusting by a user and configured to generate a time output;a comparison unit; and a detection unit; wherein the improvementcomprises: a receiver configured to receive standard time datatransmitted from a base station; a time adjuster configured to adjustthe time output based on the standard time data received by thereceiver; said comparison unit configured to compare the reproductionexpiration time of the contents with the adjusted time output; saiddetection unit configured to detect whether or not the adjusted timeoutput exceeds the reproduction expiration time of the contents; and areproduction controller configured to reproduce the contents if thedetection unit detects that the adjusted time output does not exceed thereproduction expiration time of the contents, thereby preventingreproduction of said contents after said expiration time.